2,4-Dichlorophenylhydrazine hydrochloride synthesis

Yield:-

Reaction Conditions:

Stage #1:2,4-Dichloroaniline with hydrogenchloride;sodium nitrite in water at -5; for 0.5 h;
Stage #2: with tin(ll) chloride in water at 20; for 1 h;

Steps:

5.2.5. typical procedure for the synthesis of hydrazine hydrochlorideintermediates (10)
General procedure: dissolve the substituted anline (3 mmol) in HCl aq (6 M) at -5 °C,and slowly added an aqueous solution of NaNO2 (0.23 g, 3.3 mmol).The mixture was stirred for further 0.5 h, a solution of SnCl2 (1.7 g,7.5 mmol) dissolved in concentrated HCl was added dropwise, then the resulting mixture was moved to room temperature and stirred for further1 h. The muddy mixture was filtered out, washed with a small amount of HCl solution and dried in vacuum. This desired phenylhydrazine hydrochloride intermediate was used directly without additional purification.To a solution of substituted benzyl halide 3 mmol in EtOH was added the hydrazine hydrate 30 mmol, and the mixture was stirred atroom temperature overnight till the reaction was completed monitored by TLC. The reaction mixture was concentrated to dryness, and redissolvedin a little EtOH, then added an aqueous HCl (12 M) andstirred for a while at 0 °C. The resulting precipitate was collected byfiltration and dried. This desired benzylhydrazine hydrochloride intermediatewas used directly without additional purification.

References:

Bi, Fangchao;Song, Di;Qin, Yinhui;Liu, Xingbang;Teng, Yuetai;Zhang, Na;Zhang, Panpan;Zhang, Nan;Ma, Shutao [Bioorganic and Medicinal Chemistry,2019,vol. 27,# 14,p. 3179 - 3193]

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